Printing press



y 1, 1945- w. w. DAVIDSON 6 PRINTING PRESS Filed March 18, 1940 5'Sheets-Sheet 1 ATTORNEYS.

y 1, 1945. w. w. DAVIDSON 2,374,668

PRINTING PRESS Filed March 18, 1.940 5 Sheets-Sheet 2 INVENTOR. k I v 74249 7/2/36! fiavzdaon ATTORNEYS.

y 1945. w. w. DAVIDSON 2,374,668

PRINTING PRESS Filed March 18, 1940 5 Sheets-Sheet 3 N m W i 3V uv w;|l;\\\\\\\\ .m um 1 @h u g i R 1 \j a t Q w: N \Ej q L INVENTOR.

Wa/zdfiaujoifion 7 ATTORNEYS.

y 5 w. w. DAVIDSON 2,374,668

PRINTING PRESS Filed March 18, 1940 5 Sheets-Sheet 4 INVENTOR.

m WQ/MJQVAdSOIZ I BY M ATTORNEYS.

y 1945' w. w. DAVIDSON 2,374,668

PRINTING PRESS Filed March 18, 1940 5 Sheets-Sheet 5 IN VENIOR.

ATTORNEYS.

Patented May 1, 1945 UNITEDQSTATES PATENT OFFICE 34 Claims. (01.101-142) The two most commonly used types of'printing are: direct letterpress printing, inwhich ink is applied to raised type which then printsdirectly upon the sheet to be printed; and off-. set lithographicprinting, in which the image from an inked lithographic plate is firsttransferred to a rubber blanket which in turn prints it upon the sheetto be printed. Each form of printing has its advantages and presentsspecial problems.

The present invention relates to a press which is capable of doing bothdirect and onset printing satisfactorily. Thi press uses two printingrolls, one twice as large as the other. In offset printing the smallerroll is the blanket roll. It makes one revolution in engagement with thefirst half of the large roll which bears the plate so that the ink isthus transferred to the blanket. The blanket roll thenmakes its secandrevolution in cooperation with the second half of the large roll whichhas a, platen surface for pressing the sheet in contact with theblanket, thus printing the sheet. In direct printing the smaller rollserves as the platen to press the sheet against the plate or type.carried b the large roll. However, this multi-purpose press haspresented some complications with respect to registration, stripping thesheet from the press, and delivery of the 'sheet. According to thepresent invention these complications are grippers for registration,stripping and delivery, although this presents the difflcult problemofobtaining uniformity of registration with the delivery grippersforming part of the chain delivery. If stop fingers are provided foreach of the independent gripper units positioned at diiferent pointsalong the length of the chain simultaneously greatly reduced and in factthe combination of this type of press with the other delivery, thesuccessive gripping units must be made identical and must be providedwith some means for insuring identical coaction with the printing rollsin order that they will feed successive sheets uniformly.

The delivery of sheets from a multi-purpose press has presented specialproblems because of the fact that the sheet is printed on its lower faceby offset printing and on its upper face by direct printing. It isdesirable to have the sheet delivered printed-face up so that thequality of the printing may be easily observed as the sheets aredelivered. To make the printing visible it is necessary to deliver thesheet without turning it over in the case of direct printing and afterturning it over in the case of oflset printing. This application is inpart a continuation of applicants copending application, Serial No.272,053 (now Patent No. 2,306,044) and is intended to cover the broadcommon subject matat once by using delivery chains having-twice featuresdescribed herein may be said to solve some problems relating to printingin general.

With high quality printing accurate registration of the sheet isessential. It has been the practice to provide grippers and registrationstop fingers carried by one of the printing rolls, the sheet being fedagainst the stop fingers and carried into or through the press by thegrippers. It has also been the practice to provide delivery gripperscarried by another roll or by chains to grip the sheet after it has beenprinted, pull it away or. strip it from the printing rolls, and deliverit to ap ee tW Sets Of ppers, one for registration am. one for strippingand delivery, have introduced various complications and have of coursebeen costly to manufacture, especially where chain deliveries were usedfor the sake of better delivering the sheet to a pile. Such chaindeliveries have conventionally included a plurality of grippin units atdifferent points on the chain for engaging successive sheets.

One solution to this problem is touse the same the length of theperiphery of this smaller roll and having only one gripping unitthereon. Because of this particular length of the chain, this singlegripping unit cooperates with the smaller roll for each secondrevolution thereof, or, in other words, for each printing revolutionthereof. Since there is a single gripping unit, the problem of makingand maintaining multiple gripping units identical within closetolerances is avoided. Furthermore, it has been found that with a singlegripping unit no special means is required to insure its identicalcoaction with the printing roll for successive sheets since the ordinarychain and sprocket accomplishes this result. It might be assumed thatsuch a short chain, only twice the length of the periphery of the rollaround which it extends. would be unable to draw the sheets entirely outof the bite. It has been found, however, that by extending the chaindelivery generally in the direction of feed to the press, i. e. in thedirec-- tion opposite to that from which the sheets are fed, the sheetswill be dependently delivered and furthermore can be turned over in thecase of offset printing or delivered. without turning'in the case ofdirect printing. Iii-the case of direct printing the .sheet is releasedas it approaches .the end of the chain delivery loop, at which pointand-before releaseit may pass into the bite of delivery rollers whichmay be provided vention will be apparent from. the following descriptionand from the drawings, in which:

Fig. l is a vertical longitudinal sectional view through the embodimentof the invention chosen for illustration.

Fig. 2 is a horizontal sectional view taken ap-v proximately on the line2-2 of Fig. '1' but showing the gripper at a different position.

Fig. 3 is a fragmentary vertical transverse view taken approximately onthe line 3-3 of Fig. 2.

Fig. 4 is a corresponding view taken approximately on the line 4-4of.Fig. 1.

Fig. 5 is a fragmentary longitudinal. vertical sectional view showingparticularly a transverse cross section of the gripping unit on anenlarged scale.

Fig. 6 is a somewhat similar view on a slightly smaller scale showingthe grippers closed.

Fig. 7 is a. fragmentary view taken approxi- I mately on the line 1-7 ofFig. 5 showing the plan of a gripper finger.

Fig. 8 is a view corresponding to Fig. l but showing the press convertedfor letter press printing, Fig. 1 showing it arranged for offsetprinting.

A preferred form of the invention has been chosen for illustration anddescription, in compliance with Section 4888 of the revised statutes,but persons skilled in the art will readily perceive other means foraccomplishing the same results, and the claims are therefore tobe'construed as broadly as possible, consistent with the prior art.

In the illustrated embodiment of the invention the press is carried byside frames H and includes two printing rolls, namely a large roll l2and a small roll it. The sheets are fed to these printing rolls by afinal feed unit It to which the sheets are supplied by a conveyor 86. Asillustrated in Fig. 1, the press is adapted to perform offsetlithographic printing. To this end the smaller roll l3 carries a blanketit which is first rotated in contact with a plate mounted on theperipheral urface of plate holder 20 and then with a platen 2|. Ofcourse, the plate need not be a lithographic plate, but for offsetprinting it usually will be. Lithographic plates must be dampened andinked successively and; accordingly, dampening rolls 22 and inking rolls23 are provided, the plate holder 20 carrying the plate into contactwith the last roll of each set.

gather such ink, however, and in turn applies it to the blanket it ofthe smaller roll ll, which maybe called the blanket roll. A sheet ofpaper to be printed is then fed between the printing rolls l2 and i3and, the ink image thus applied to the blanket is printed on the sheet.The sheet then passes from between the printing rolls, and the blanketroll next rotates on the plate to begin a new cycle of the process.

Direct printing usually is performed with raised type or the raisedportions of a plate. In Fig. 8,

the plate or type is represented by the removable type 2t. This typeruns in contact with the final inking roll 23 and then prints directlyonto the sheet. In this instance the other half of the large roll I2 andthe second revolution of the smaller roll l3 may be idle. The last ofthe dampening rolls 22 should be moved so as not to touch the type 26.Preferably, the dampening rolls together with portions of the side walls21 comprise a removable dampening unit which, as seen in Fig.8, has beenremoved. Likewise, in converting the press for letter press printing(printing with raised surfaces) the blanket iii of Fig. 1 may bereplaced by a special surface member 28 which may be formed ofanymaterial heretofore .used for letter press printing. For conventionaltype the material should be one suitable for the process known as makingready.

It will be observed that in the offset printing of Fig. 1 the undersideof the sheet is printed, and in orderfor the printing to be visible forinspection as the press continues to print it is necessary for the sheetto be turned over in delivery. In direct printing, as shown in Fig. 8,"

on the other hand, the sheet is printed on the upper surface and istherefore desirably delivered without being over-tumed so that it mayeasily be viewed for inspection. Thus, it is seen that it is desirableto have delivery means which will turn the sheet over or deliver itwithout tuming it at will.

In offset printing the sheet has a tendency to stick to the blanket I8,especially when a large area of the blanket is inked, and it isdesirable to provide some means for, positively pulling the full lengthof the sheet entirely from the blanket. Furthermore, with directprinting there are often a few lines of type near the leading end of thesheet and then a few lines of type near the rear end of the sheet withno intervening type, as illustrated in Fig. 8. Through-the interveningposition the large printing roll does ,not engage the plate, and usuallythese grippers are carried The water applied by the dampening rolls 22 Imaintains a film on the non-image portion of the plate, and this film ofwater in turn prei vent this portion of the plate from gathering by theplaten roll so that they serve the additional function of initiallystripping the sheet from the inked printing surface of the otherprinting roll. These grippers pass the sheet to a second set of gripperswhich complete the task of stripping the sheet. If these second grippersare mounted on a pair'of spaced chains, they may also deliver the sheetto its ultimate point "of stacking. Otherwise, they usually pass thesheet on either to a chain delivery comprising a third set of gripperscarried by a pair of spaced chains or to delivery rollers, either ofwhich moves the sheet to its ultimate point of delivery.

For some printing extremely accurate registration is desirable. This isparticularly true for multi-color work in which a sheet is printed firstwith one color and later with one or more other colors and the colorsshould be perfectly registered with respect to one another. In short, itis essential for a satisfactory, high quality press that successivesheets be positioned accurately in the same position on the type orblanket rolls so that the printing will appear at the same position onall sheets of a given run. This necessity would seem to be a positivebar to any attempt to save money by utilizing the grippers of the chaindelivery for the registration grippers since the,

use of a plurality of grippers for successive sheets obviously makesuniformity of registration of successive sheets extremely difficult.Even if successive gripper units could be made identical and if means isdevised for assuring the uniform coaction between these successivegrippers and the printing roll around which they rotate, there is thedifficulty of maintaining them identical in spite of wear.

According to the present invention these seemingly irreconcilableconsiderations are reconciled. At the same time that highly satisfactoryregistration is secured by the chain delivery grippers, the chaindelivery itself is made more economical than heretofore,

One key to the solution is using a chain delivery with a single grippingunit, indicated generally by reference numeral 29. This in turn is madepossible by carrying the chain delivery around a printing roll whichmakes more than one revolution for each printing (the roll I3) andmaking the chains 3| short enough to return the gripping unit to thefeeding position for each printing. In the simple form illustrated, inwhich the roll I3 makes two revolutions for each printing, the chain isonly twice the length of the periphery of roll I3. This is anexceptionally short length for the delivery chains, particularly sincethe chains go around one of the printing rolls, and except for thisinvention would appear to be an insufficient length for the purposes ofstripping a long sheet from the blanket roll and carrying a long sheetthrough the press'when the sheet is not gripped by the printing rolls.

By using a single gripping unit 29 the problem of obtaining andmaintaining identity between a plurality of gripping units is avoided.Furthermore, it has been discovered that by driving the chains 3| bysprockets 32 mounted on the printin roll l3 (or otherwise rotatingdirectly therewith) the uniformity of coaction between the grippers andtheroll on successive printings is entirely satisfactory. This has beenfound to be true with a conventional roller chain and correspondingsprocket, and' it is believed that it would be true of any chain andsprocket in which the chain seats between the teeth of the sprocket,either by a Vtype of engagement with the teeth or in the illustratedform by seating uniformly somewhere on the bottom curvature 33 betweenthe teeth 34. Even wear has no objectionable effect because there issubstantially no wear during one printing run, or evenmany runs, andwhen the plate is changed for a different run, registration adjustmentsmust b made anyway.

If desired, special shaping of the leading faces of the teeth and thesurface between them may be provided to be more obviously dependable asto uniformity of positioning of the roller in the sprocket, but this hasbeen found to be unnecessary. However, it is preferred at present thatthe teeth 34 be a little thicker from face to face of the sprocket thanis conventional for a given chain size so that, as seen in Fig. 3, theywill fit snugly within the links of chain 3| so as to prevent side playthereof. The teeth are of course tapered at their points. prevented bymaking one sprocket adjustable toward and from the other. As a matter offact, further time may show that it is not necessary to prevent sideplay since the chain will never have a chance to move much laterallybetween its reception of the sheet and the delivery of the sheet to thebite. The chains also extend around sprockets 35 which are driven by thechains.

It is somewhat desirable that the gripping unit be located entirelywithin the imaginary cylinder formed in part by the surface of theblanket l8, as this will make it unnecessary to notch the other printingroll I2 to receive the gripping unit. It is not diflicult to shape thegripping finger 36 to accomplish this result in so far as the grippingfinger is concerned. However, it is desirable that the gripping fingerbe raised a fairly substantial distance as seen in Fig. 5 in order tofacilitate feeding the sheet 31 beneath it. It is evident, however, thatfor accurate registration purposes the stop against which the sheet isregistered must extend all the. way between the gripping seat 38 and thegripping finger 36. According to the present invention this isaccomplished by providing a stop 39 carried by the gripping finger 36instead of being carried by the seat 38 as is customary. Thus, it isevident that as the gripping finger 36 is lowered, the stop 39 islowered likewise. .This stop is preferably made arcuate as shown so thatit may fit fairly closely to the gripping seat 38.

The'gripping seat 38 comprises the gripp r bar which supports the entiregripping unit. As'seen best in Fig. 3, the gripper seat or bar 38 issecured directly to the chain 3!. The chain 3| is provided with aspecial link plate 4| having a lug 42 bent therefrom. This lug fits intoa slot 43 in the gripper bar 38 and is secured therein by a screw 44.The same construction is duplicated at the other end of the gripper bar38. The gripper bar carries a gripper rod 46, which may be journaled intwo or more brackets 41 carried by the gripper bar 38. The rod may bemaintained in its axial position by collars 48 secured to the rod 46 bysetscrews.

A plurality of the gripper fingers 36 are mounted on and actuated by theripper rod 46. It is that they can slide along the rod and providingactuating and positioning collars 49. Each collar 49 may desirably bepositioned between two legs SI of once! the gripping fingers 38. Whensecured rigidly-to the rod 46 by a setscrew 52, it will prevent movementof the-gripping finger 38 in either direction along the rod 46. The sideof the rod Side play may also be.

46 against which the screw 52 bears is preferably flattened, as seen inFig. 5, so that the collar 49 is in effect keyed to'the rod 46. As seenbest in Fig, 5, the collar 49 is notched at 53 an has a loose engagementwith the finger 36. When the rod 46 is rotated in a counterclockwisedirection as seen in Fig. 5, the collar 49 engages the bottom of thefinger 36 and raises the finger 36. When the rod 46 is rotated in theopposite direction, the finger 36 is lowered against the seat 38 byspring 54. As the finger 36 seat en the seat 38 or rather on the sheet3'! thereon, rod 46 and collar 49 continue to turn slightly so that thecollar 49 ceases to engage the bottom of finger 3-6. This makes thegripper finger 36 independent of the collar 49 and henc independent ofthe other gripper fingers so that each gripper finger is pressed by itsown spring 54. If desired, one or more of the springs may be providedwith an additional spring 56 so as to grip the sheet 31 quite tightly.This has been found to be particularly desirable in the case of offsetprinting so as to dependably strip the sheet from the blanket.

The gripper rod 46 is actuated in the opening direction by an arm 58rigidly mounted thereon and carrying a cam-following roller 59,stationary cams being provided for actuation of the roller 59. It isggnstantly urged in the gripping direction by springs 66. With thismethod of actuation the rod 46 extends through a notch 6| in sprocket32. It is only necessary to omit one tooth for this notch and it hasbeen found that this does not interfere with the uniformity of theregistration. If peculiar conditions should so require, however, the rod46 could be actuated from within the sprocket 32, as by an actuatorpermanently extending through and carried by the sprocket and thereforenot requiring the peripheral notch 6|.

Adjacent the roll l3 a cam 62 is provided for opening the gripperfingers 36 at the proper time for receiving the sheet 31 and closing thegripper fingers while the sheet is pressed against the stops 39. Foroffset printing a release cam 63 is provided along the bottom run of thechain 3|, and for direct printing a removable cam 64 (Fig. 8) isprovided near the end of the upper run of chain 3| or, in other words,adjacent the end loop of the chain remote from the roll l3. With offsetprinting the gripping unit 29 draws the leading edge of the sheet aroundthe sprockets or rather around rollers 66 or the like coaxial withsprockets 35. In this manner the sheet is turned over and, when it isreleased by operation of cam 63, it

drops face down into receiving box 61 positioned as shown in Fig. 1.

In the case of direct printing a receiving box 68 is positioned as seenin Fig. 8 and, when the leading end of the sheet 31 is released as seenin of the sprockets 35. Preferably, the rollers 66 and 69 are adjustablealong their respective shafts so that they may be placed on the marginof the sheet oralong some other line where rollers 69 will not smear thefresh ink thereon. It has been found that rollers 66 do not smear theink in the case of offset lithographic printing. However, if

desired, the rollers 66 may be replaced for offset printing by rollershaving knife edges or toothed v rollers to prevent the smearing of theunderside of the sheet, which in this instance will be printed. Ineither event the pressure rollers 69 will be removed or raised highenough so that they will not press the sheet against a sharp edged orpointed roller 66. 7

Any suitable means may be provided for insuring proper entry of thesheet into the collection boxes. For example, the direct printed sheetsmay pass over a guide plate (not shown) between rollers 66 and the box68. As seen in Fig. 1 for offset printing, stop arms 13 may be carriedby the box 6'! to engage the leading edge of the sheet and stop thesheet after it has been released. The gripperbar 38 is preferablynotched as seen at 14 to receive the ends of the arms I3 so that therewill be no chance of the sheets slipping past the arms 13. The arms 13are preferably provided with a crook or slightly upwardly facingshoulder I6 so that the following of the leading edge of the sheet willbe retarded and the sheet will in efiect be thrust slightly to the leftas seen in Fig. 1 to strike the bottom of the collecting box 61. Thearms 13 may be adjustably carried by a bracket ll which in turn may beadjustably mounted on the box 61 so that a wide variety of sheet lengthsmay be dropped against the back of the box 6i.

0f course,'the sheet should always be released shortly before it strikesthe stop arm 13 and, accordingly, the cam 63 is likewise madeadjustable. As seen best in Fig. 4, this cam is mounted on a slidingbracket 19 which slides in slideway 19 except when locked by screwing inscrew 8i. In order that the pressure of cam 63 on camfollowing roller 59may not flex the chain too greatly and hence cause the gripping unit 29and with it the leading edge of the sheet to be positioned improperlywith respect to stop arms 13, a chain guide or backing plate 83 may beprovided. As seen best in Fig. 4, this backing plate may engage a roller84 rotatable on gripper rod 46. The backing plate 83 may be carried by abracket 86 carried by cross rods 81 extending between the side plates H.I

Instead of dropping the sheets into collection boxes-61 or 66, they maybe dropped onto suitable pile mechanism in which the support surface isgradually lowered as the height of the stacked sheets increases to keepthe top of the stack approximately at a constant position. The spacebelow box 61 is left clear for such mechanism. Likewise, the sheets maybe dropped onto a conveyor which carries the sheets to a stack and suchconveyors may be adjustable to receive the sheet either in the positionof offset printing release or the position of direct printing release.

Operation Although the operation will be apparent from the foregoingdescription and from the drawings, it may be supplemented briefly forthe sake of clarity. The sheets will be fed one at a time to the gripperfingers 36 as seen in Fig. 5. The feeding mechanism may be of any formso long as it feeds the sheets in-properly timed relationship and withaccurate lateral and angularpositioning. As diagrammaticallyillustrated, the separated sheets will be moved forwardly by the biasedconveyor l6 and simultaneously urged against a side guide 9|. The sideguide will accurately position the sheets both laterally and angularly.The sheets are fed against stop fingers 92 which will be stationary atthis time. Thereafter, pressure roll 93 will be lowered to press thesheet against stationary feed roll 94, whereupon gear segment 96 will beactuated to smoothly and associated parts is controlled by cams rotatingwith the large roll It.

The grip fingers 33 are opened to receive sheet 31 by cam 32 whichoperates through cam follower 59, arm 58, rod 46 and collar 49, thenotch 53 of which engages the bottom of grip finger .36.

As-roller 59 runs off of cam 32, the grip fingers 36 will be allowed toclose under the influence of springs 54 and 56 (Fig. 7) and grip thesheet by pressing it against the gripper bar 38.

The sheet thus gripped will be carried into the bite between rolls l2and I3, where it will be printed. ,In the case of lithographic printingthe sheet will be continuously gripped by the two printing rolls l2 andI3 and hence each sheet will be controlled by them until the printing ofthe sheet is complete. In the case of letter press printing there may beintervals during the printing of a single sheet when the sheet'is notgripped by the printing rolls, and in these intervals the sheet willnevertheless be moved forwardly by the gripping unit 29 carried by thechain 3|. After the leading edge of a direct printed sheet has passedinto the bite between rollers 66 and 69, which may be regarded as'bothfeeding and delivery rollers, the cam 64 will release the leading edgeof the sheet and the sheet will then be advanced by the driven roller 66and the pressure roller 69 and will eventually be discharged by theminto the collecting box 68. For sheets short enough to leave theprinting rolls before being released by gripper 29, rollers 69 are notnecessary, but are desirable.

In the case of offset printing the pressure roller 69 may be omitted orraised, cam 84 will be removed, and the gripping unit 29 will continueto grip the sheet until it has carried it around the rollers 66, whichin this instance may be special v non-smearing rollers, as previouslystated. The distance from roll [3 along the upper run of chain 3| andaround the roller 66 to the bottom thereof is sufficient so that thelongest sheets for which the. press is designed will be completelystripped from the blanket roll |3. Thereafter, the gripping unit 29 willbe operated by cam 63 to release the sheet which will strike stop arm 13and be guided by it into the collection box 61. Correct positioning ofthe sheet as it strikes the stop arm 13 will be assured by backing plate83 which prevents undue flexing of the chain under the influence of thepressure of cam 63 on roller 59.

For offset lithographic printing the plate is mounted on the plateholder 20, a conventional rubber blanket is mounted on the roll I 3, andthe segment 2| serves as a platen. The roll I2 may be called aplate-platen roll; and the roll I 3, a transfer roll. The plate or plateholder rotates in contact with the final dampening roll 22 and with thefinal inking roll 23, then applies the inked image to the blanket l8,and this blanket during the next revolution of the smaller roll |3prints the image on the underface of the sheet of paper, pressing itagainst platen 2|. Both of the final rolls 22 and 23, normallyresiliently urged toward roll l2, are shifted by cams, diagrammaticallyrepresented at 91, carried by the plateplaten roll, preferably by theplaten segment 2|,

so as not to engage this platen segment. 7

For direct printing the plate holder 20 is removed and the platensegment 2| is replaced by-a type or plate holder which may be similar tothe plate holder 20 or may beof a kind that is capable of receivingremovable type, for example as shown at 20'; The plate holder, whetherit be of the kind shown at 20 (only of lesser radius) or the kind usingremovable type as shown at 20, is applied to the drum in the positionordinarily occupied by the platen 2| so that the sheets will be fed toit instead of to the platen 2|. The dampening unit including rolls 22and frame portion 21 is removed. The plate or type 23 in the position ofthe platen 2| is inked and the ink is printed thereby directly to theupper face of the sheet,

the roll I 3 now serving as a platen. The coveringv of roll |3 will bechanged to correspond to the type of printing surface applied to theroll l2. Thus, if the roll I2 is provided with a rubber plate, therubber blanket l8 may sometimes be left on the roll l3. For metal typeor plates, especially electrotypes, it may be preferred to substitute ablanket oftougher and harder rubber or other slightly resilient matter.In other instances a conventional surface, such as tympan sheet, may bedesired, which incidentally is suitable for the process of making ready.Any desired surface may be used on roll l3.

From the foregoing it is seen that a combination of printing press andregistering, stripping and delivery means is provided which is extremelysimple and economical to manufacture, registers sheets accurately,carries them between the printing rolls when they are not grippedthereby, strips them from the printing rolls, and deposits them on apile with the printed side up regardless of whether the underface orupper face is printed. All of this is accomplished largely by virtue ofusing a single gripping unit which in .tum is made possible by makingthe length of the chains carrying it correspond to a multiple of theperiphery of one of the printing rolls, this printing roll making tworevolutions for each 1 printing. By chain and sprocket" are meant anymembers which operate in like manner and include interengagingpositioning formations.

I claim:

1. A printing press including a plate-platen roll adapted to bear aplate and a platen for offset printing and a plate or type for directprinting, a second roll adapted to have a transfer surface thereon a dmaking two revolutions for one revolution of he plate-platen rollwhereby it rotates the transfer surface first in contact with the plateand then in cooperation with the platen,-said second roll. also servingas a platen for direct printing, and chain delivery means for feedingsheets to the bite and for delivering sheets from the bite includingchains extending around said second roll and extending away therefrom, asingle gripper unit carried by the chains and cooperating with therolls. for each printing, and means for causing said gripper unit torelease the sheet approximately as it reaches the remote loop of thechains or optionally after it has passed around said loop whereby thesheet may be released with the printed face up regardless of which faceis printed.

2. A printing press includinga plate-platen roll adapted to bear a plateand a platen for offset printing and a plate or type for directprinting,

a second roll adapted to have a transfer surface thereon and making tworevolutions for one revolution of the plate-platen roll whereby itrotates the transfer surface first in contact with the plate and then incooperation with the platen, said second roll also serving as a platenfor direct printing, means for feeding sheets toward the bite, and chaindelivery means for delivering sheets from the bite including chainsextendingaround said second roll and extending away therefrom generallyin the direction of feed, a gripper unit carried by the chains, andmeans for causing said. gripper unit to release the sheet before itpasses around the remote loop of the chains or optionally after it haspassed around said loop whereby the sheet may be released with theprinted face up regardless of which face is printed.

8. A printing press including a plate-platen roll adapted to bear aplate and a platen for offset printing and a'plate or type for directprinting, asecond roll adapted to have a transfer surface thereon andmaking two revolutions for one revolution of the plate-platen rollwhereby it rotates the transfer surface first in contact with the plateand then in cooperation with the platen, said second roll also servingas a platen for direct printing, means for feedingsheets toward thebite, and chain delivery means for delivering sheets from the biteincluding chains extending around said second roll and extending awaytherefrom generally in the feeding direction, a shaft spaced from thesecond roll, sprockets on the shaft driven by and supporting the chain,a roller keyed to the shaft, a gripper unit carried by the chains, andmeans for causing said gripper unit to release the sheet before itpasses around the roller or optionally after it has passed around saidroller whereby the sheet may be released with the printed face upregardless of which face is printed.

4. A printing press including a plate-platen roll adapted to bear aplate and a platen for offset printing and a plateor type for direct fordirect printing, means for feeding sheets toward the bite, and chaindelivery means for-delivering sheets from the bite including chainsextending around said second roll and extending away therefrom generallyin feeding direction, a

shaft spaced from the second roll, sprockets on the shaft driven by andsupporting the chain, a roller keyed to the shaft, gripper unit carriedby the chains, means for causing said gripper unit to release the sheetbefore it passes around the roller or optionally after it has passedaround said roller whereby the sheet may be released with the printedface up regardless of which face is printed, and a pressure rolleradapted to press the sheet against the driven roller to continue themovement of the sheet after its'release by the gripperunit.

5. A printing press including printing rolls, the first of which makesmore than one revolution for each printing and the second of which has aportion cooperating therewith for printing, and chainregistration-delivery means including a chain extending around saidfirst roll, having a, length corresponding to more than the periphery ofsaid first roll and carrying a single gripping unit cooperating withsaid rolls for successive printings by cooperation of said first rolland said portion,

6. A printing press including printing rolls, the

first of which makes more than one revolution for each printing and thesecond of which has a portion cooperating therewith for printing, andchain registration-delivery means including a chain extending aroundsaid first roll, having a length corresponding to more than theperiphery of said first roll and carrying a single gripping andregistration-stop unit cooperating with said rolls for successiveprintings by cooperation of said first roll and said portion, said chainextending around and being drivenby a sprocket angularly rigid with thefirst roll and having a seating engagement with the links of the chain.

7. A printing press including printing rolls, one of which makes morethan one revolution for each printing, and chain registration-deliverymeans including a chain extending around said one roll and having alength corresponding to more than the periphery of said roll andcarrying a single gripping and registration-stop unit cooperating withsaid roll for successive printings, said chain extending around andbeing. driven by a sprocket angularly rigid with the roll.

8. Ina printing press including a printing roll,

the sheet against the roller means, and collection means positioned toreceive the sheet where it is ejected by the roller and roller meanswithout being turned over or where it is released by the gripper unitafter being carried around the roller means. v

9. In a, printing press including printing rolls, means for feeding asheet toward the bite of the printing rolls, and chain delivery meansincluding chains passing around one of the printing rolls and awaytherefrom in the feeding direction, a gripping unit adapted to seize andgrip the sheet as-the unit passes adjacent said roll, and means forreleasing the gripping unit after it has carried the sheet around a loopin the chain to turn the sheet over.

10. In a printing press including printing rolls, means for feeding asheet toward the bite of the printing rolls, and chain-delivery meansincluding chains passing around one of the printing rolls and awaytherefrom in the feeding direction, a gripping unit adapted to seize andgrip the sheet as the unit passes adjacent said roll, means forreleasing the gripping unit after it has carried the sheet around a loopin the chain to turn the sheet over, and sheet-stopping means effectiveto overcome the momentum of the sheet as it is released whereby thesheet may be allowed to drop on a pile.

11. A printing press including printing rolls and chain registrationmeans including a chain formed in a closed loop, one portion of whichfrom the roll by the chain, and means for releasing the g ipping unit ata position spaced from said roll after it has drawn the sheet therefrom.13. A printing press including printing rolls, chain registration meansincluding a chain formed in a closed loop, one portion of which moveswith the periphery of one roll as it isengaged by the other, a singlegripping and registration-stop unit carried by the chain, cooperatingwith said roll for successive printings, and after each such cooperationbeing drawn away from the roll by the chain, and means for releasing thegripping unit at a position spaced from said roll after it, has drawnthe sheet therefrom, and means for feeding a sheet to the stop andgripping means for each printing. 14. The combination of a press'havingprinting rolls adapted to print optionally the upper or the lower faceof a sheet, and delivery means including gripper means and meansincluding endless fiexible means for controlling the gripper means todraw the sheet away from a roll of the press and deliver it optionallyeither face up, said delivery means in one instance carrying the sheetaround one end of the loop to turn it over.

15. A gripper unit for registering sheets for printing presses,including a gripper seat, a grip finger pivoted with respect to the seatto open therefrom to receive a sheet and to clamp the sheetthereagainst, and ,a registration-stop member carried by the grip fingerand movable with it with respect to the seat to accurately position thesheet as to its entry within the gripper unit, the face of said stopmember being approximately arcuate about the pivotal axis of the gripfinger.

16. A printing press including a plate-platen roll adapted to bear aplate and a platen for offset printing and a plate or type for directprinting, a second roll adapted to have a transfer surface thereon andmaking two revolutions for one revolution of the plate-platen rollwhereby it rotates the transfer surface first in contact with the plateand then in cooperation with the platen, said second roll also servingas a platen for direct printing, means for feeding sheets toward thebite, and chain delivery means for delivering sheets from the biteincluding chains extending around said second roll and extending awaytherefrom generally in the direction of feed, a gripper unit carried bythe chains, and means for causing said gripper unit to release the sheetapproximately as it reaches the remote loop of the chains or optionallyafter it has passed around said loop whereby the sheet may be releasedwith the printed face up regardless of which face is printed.

17. A printing press including printing rolls, the first of which makestwo revolutions for each printing and the second of which has aprinting.

portion adapted to cooperate therewith for printing, and chainregistration-delivery means including a chain extending around saidfirst roll and having a length corresponding to twice the periphery ofsaid first roll and carrying a single gripping andregistration-stop-unit cooperating with said rolls for successiveprintings by cooperation between said first roll and said portion.

18. A printing press including upper and lower printing rolls of'whichthe lower roll is an inkbearing roll adapted to print the ink on asheet, and chain delivery means including chains extending around andaway from the lower roll, gripping means carried by the chains andadapted to strip a sheet from the lower roll and deliver itprinted-side-up at a point spaced therefrom;

and stop fingers positioned uniformly with respect to the lower rolleach time the gripping means,

passes therearound and moving with it for cooperating with the grippingmeans as the gripping means passes around said lower roll and accuratelyregistering asheet with respect to the lower roll.

19. A printing press including printing rolls of which one is anink-bearing roll adapted to print the ink on a sheet, and chain deliverymeans including chains extending around and away from the said roll,gripping means carried by the chains and adapted to strip a sheet fromthe said roll and deliver it at a point spaced therefrom, and stopfingers positioned uniformly with respect to the said roll and movingwith it each time the gripping means passes therearound for cooperatingwith the gripping means as the gripping means passes around said lowerroll and accurately registering a sheet with respect to the said roll.

means forming an angle into which the sheet is' fed and which, inclosing of the finger, moves relatively in a direction opposite to thedirection of feeding.

21. A printing press including printing rolls, a gripping unit passingaround one of said rolls in predetermined relationship thereto andincluding a grip base, a movable grip finger and registration-stop meanscarried thereby, and feeding means for feeding a sheet into the grippingunit at such speed and direction that the sheet will be buckled by thestop means outside of the grip finger as the grip finger is closed; saidstop means extending continuously from the grip finger when it is opento the grip base whereby a sheet fed betweenthe grip finger and the gripbase cannot possibly slip past the stop means.

22. A two-purpose press having printing rolls adapted to printoptionally the upper or lower face-of a sheet with different methods ofprinting, and delivery means for delivering the sheet eitherface-up sothat, regardless of which face is printed, the printed face may bevisible on the delivery pile for inspection.

- means for releasing the sheet gripper after it has traversed said loopand turned' over the sheet, to deliver the sheet with its other face up;the

last-named means for releasing the gripper being adjustable to releasethe gripper at the earliest possible moment afte'r traversing the loopwhich will produce satisfactory and dependable delivery of the sheet;the sheet in the position to which it drops upon said release beingsubstantially visible from beyond the loop.

24. Sheet delivery apparatus adapted to turn a sheet over beforedelivering it, comprising a sheet gripper adapted to engage the sheet tobe delivered and to thereafter move through a loop to reverse itsdirection of movement and means for releasing the sheet gripper after ithas traversed said loop and turned over the sheet; said means beingadjustable to release the gripper at the earliest possible moment aftertraversing the loop, which will produce satisfactory and dependabledelivery of the sheet; the sheet in the position to which it drops uponsaid release being substantially visible from beyond the loop.

25. Chain feed and delivery apparatus for feeding sheets to the bite ofa printing press formed by two members of which one is a cylinderrotating twice for each impression of a given printing member associatedtherewith comprising: chains extending generally around said cylinderand away therefrom and of such length as to make one cycle for each tworevolutions of the cylinder, a single gripper unit carried by the chainsand 00- operating with the cylinder for each printing, means for causingthe gripper unit to open to receive the sheet before the gripper unitreaches the bite and for causing it to close on the sheet and carry thesheet to the bite in accurate registration with the printing member andmeans for causing the gripper unit to release the sheet after it haspulled at least the leading end of the sheet away from the cylinder.

26. Sheet delivery apparatus for delivering a sheet optionally eitherside up including two pairs of axially aligned sprockets disposed witheach sprocket in alignment with a sprocket of the other pair, rollermeans between the sprockets of one pair and rotatably mounted coaxiallytherewith, chains extending around the sprockets, a gripper unit carriedby the chains and engaging a sheet in the vicinity of the other pair ofsprockets, means for causing the gripper unit to release the sheetoptionally either before or after drawing the 4 sheet around the rollermeans, a pressure roller adapted to press the sheet against the rollermeans, and collection means positioned to receive the sheet Where it isejected by the roller and roller means without being turned over orwhere it is released by the gripper unit after being carried around theroller means.

2'7. The combination of a printing press ineluding a printing roll and amember forming a printing bite therewith, chains extending partly whilethe leading edge of the sheet is moving with the gripping means, andmeans for again opening the gripping means after the gripping means hascarried the sheet away from the printing roll to release the sheet atthe desired delivery point; the construction and relation of the partsbeing such that the sheet is held in predetermined registration with thegripping means as the gripping means is closed, and the gripping meansis rigidly disposed with respect to the printing roll with the sheet inpredetermined registration with the printing roll as the sheet entersthe bite.

28. The combination of a printing press includlng a printing roll and amember forming a printing bite therewith, chains extending partly aroundthe axis of the printing roll, rotating with the printing roll andextending away there-' from, gripping means carried by the chains and attimes rigidly disposed with respect to the printing roll, feeding meansfor feeding a sheet to the gripping means and moving it .as fast as thegripping means moves to cause its leading edge to move with the grippingmeans, means for opening the gripping means to receive a sheet as it isfed to the gripping means and for closing the gripping means after thesheet is fed thereto and while the leading edge of the sheet is movingwith the gripping means, and means for again opening the gripping meansafter the grippingv means has carried the sheet away from the printingroll to release the sheet at the desired delivery point; theconstruction and relation of the parts ybeing suchthat the sheet is heldin predetermined registration with the gripping means as the grippingmeans is closed, and the gripping means is rigidly disposed with respectto the printing roll with the sheet in predetermined registration withthe printing roll as the sheet enters the bite, and stop meanspositioned uniformly with respect to the printing roll each time thegripping means receives a sheet, for cooperating with and movingwith thegripping means and accurately registering a sheet with respect to theprinting roll.

29. In a printing press, sheet feeding mechanism, a printing couplecomprising an upper drum, and a lower drum, the latter being 0nehalf thediameter of the upper drum and having its longitudinal axis offset, inthe direction from which the sheets are fed, from the vertical planewhich includes the longitudinal axis of the upper drum, means-formounting either a lithographic plate or a type plate upon the uppercylinder, means whereby the lower cylinder may act either as an ofisetsurface or a platen depending upon the type of plate used on the uppercylinder, and means for delivering printed sheets either forwardly fromthe printing couple in the event that direct printing is being done, orrearwardly toward the sheet feed in the event that offset printing isbeing done, whereby the sheets are in both cases stacked with theirprinted faces up.

30. Chain registration-delivery means for a ,press having a printingroll which makes two ciated with the roll from the time it closes upon Ithe sheet untilit delivers the sheet to the point at which printingthereof occurs.

31. A printing press including printing rolls, the first of which makesmore than one revolution for each printing and the second of which has aportion cooperating therewith for printing, and chainregistration-delivery means including sprockets rigidly mounted withrespect to said first roll and rotating therewith, a pair of chainsextending around said sprockets and each having a length correspondingto said number of revolutions of said sprockets and a gripping unitcarried by said chains and cooperating with said roll for successiveprintings by cooperation of said first roll and said portion, means forfeeding a sheet for each printing and positioning it to be gripped bythe gripping unit in a predetermined position for producing apredetermined registration when the grippingunit carries the sheet tothe printing position, and means for opening the gripping unit andclosing it upon the sheet so positioned; said gripping unit from thetime that it closes upon the sheet until after it has carried the sheetto the position of printing being carried by portions of the chainswhich are wrapped in engagement with the sprockets whereby thepositioning of the gripping unit with respect to the roll will be rigidduring said time.

32. A printing press including printing rolls, the first of which makesmore than one revolution for each printing and the second of which has aportion cooperating therewith for printing, and chainregistration-delivery mean includin sprockets rigidly mounted withrespect to said first roll and rotating therewith, a pair of chainsextending around said sprockets and each having a length correspondingto said number of revolutions of said sprockets and a gripping unitcarried by said chains and cooperating with said rolls for successiveprintings by cooperation of said first roll and said portion, means forfeeding a sheet for each printing and positioning it to be gripped bythe gripping unit in a. predetermined position for producing apredetermined registration when the gripping unit carries the sheet tothe printing position, and mean for opening the gripping unit andclosing it upon the sheet so positioned.

33. A gripper unit for registering sheets for printing presses,including a gripper seat, a grip finger pivoted with respect to the seatto open therefrom to receive a sheet and to clamp the sheetthereagainst, and a registration-stop member'to accurately position thesheet as to its entry within the gripper unit, the face of said stopmember being approximately arcuate about the pivotal axis of the gripfinger.

34. In a two purpose press, the combination of a printing couplecomprising a first cylinder adapted to carry a printing plate on oneportion of its periphery and a platen surface on another portionthereof, and a second cylinder cooperating therewith and serving attimes as a transfer surface for offset printing on one side of a sheetand at times as a platen surface for print-- ing on the other side of asheet, and delivery means for delivering a sheet which has been printedin the couple either face up so that regardless of which face isprinted, the printed face may be visible on the delivery pile forinspection.

WILLIAM WARD DAVIDSON.

